''Elymus elymoides'' is a species of wild rye known by the common name squirreltail. This grass is native to most of North America west of the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it fl ...

and occurs in a number of ecosystems, from the

alpine zone Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets ...

to desert sage scrub to valley grassland.

Description

''Elymus elymoides'' is a perennial

bunch grass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennial ...

growing to around in height. Its erect solid stems have flat or rolled leaf blades. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on ...

is up to long and somewhat stiff and erect, with

spikelets A spikelet, in botany, describes the typical arrangement of the flowers of grasses, sedges and some other Monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the spikelet that ...

one or two centimeters long not counting the awn, which may be 9 centimeters long and sticks straight out at maturity, making the inflorescence look like a bottlebrush (see main image), and aiding wind dispersal of the seeds. In contrast, the early-season spike is compact and reddish, as in the images at left. This grass is considered very good forage for

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated sh ...

. It is best for grazing during the winter, when it is small and green. It becomes less palatable to livestock when its awns grow long and sharp at maturity.

Economics and competition

The genus ''Elymus'' is a part of the

Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

, the grass family, which is the most economically important plant family to modern human civilization. Evolving 55 million years ago, members of the Poaceae produce wheat, rice, and barley cereal grains. ''Elymus elymoides'' (also known as squirreltail) is a specific type of wild rye that experiences competitive forces when introduced to invasive species, such as

cheat grass ''Bromus tectorum'', known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, south ...

(''Bromus tectorum''). ''E. elymoides'' experiences a decrease in fitness when growing concurrently with ''B. tectorum'', leading to natural selection acting negatively on ''E. elymoides''. This is perhaps best seen in the

Great Basin The Great Basin is the largest area of contiguous endorheic basin, endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California ...

, as the dry environment makes water a limiting resource, resulting in competition over it. ''B. tectorums advantages may be due to its ability to re-engineer that particular ecosystem's scarce water supply. ''B. tectorum'' affects ''Elymus multisetus'' similarly, indicating that the trait causing decreased fitness is shared among the entire genus ''Elymus''. Competition also occurs between ''E. elymoides'' and the invasive crested wheatgrass (''Agropyron cristatum''). When introduced, crested wheatgrass negatively affects mature ''E. elymoides'', despite being able to effectively compete at the seedling stage. If crested wheatgrass is used in rehabilitation or restoration of a site, then co-planting a native bunch grass, such as ''E. elymoides'', may be helpful in preventing a crested wheatgrass

monoculture In agriculture, monoculture is the practice of growing one crop species in a field at a time. Monoculture is widely used in intensive farming and in organic farming: both a 1,000-hectare/ acre cornfield and a 10-ha/acre field of organic kale ...

. Because ''E. elymoides'' populations decline when introduced to certain populations, squirreltail may benefit more from a monoculture setting. This characteristic is supported by another species, ''Elymus nutas''. However, although it is successful as a monoculture food source, it results in a reduction of carbon transfer and decreased

soil health Soil health is a state of a soil meeting its range of ecosystem functions as appropriate to its environment. In more colloquial terms, the health of soil arises from favorable interactions of all soil components (living and non-living) that belong ...

when grown alone.Zhao, L., Chen, D., Zhao, N., Li, Q., Cheng, Q., Luo, C., . . . Zhao, X. (2015). Responses of carbon transfer, partitioning, and residence time to land use in the plant–soil system of an alpine meadow on the Qinghai-Tibetan Plateau. ''Biol Fertil Soils Biology and Fertility of Soils'', 781-790. Retrieved November 1, 2015. To preserve a prosperous ''Elymus elymoides'' food source, one must take into consideration its effects on the soil when grown alone, and its responses to competitive forces if grown with other plants.

Subspecies

Subspecies include: *''E. e.'' ssp. ''brevifolius'' - widespread *''E. e.'' ssp. ''californicus'' - occurs in the western half of the species range *''E. e.'' ssp. ''elymoides'' - widespread *''E. e.'' ssp. ''hordeoides'' - limited mostly to the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

References

External links

* *
Jepson Manual Treatment: ''Elymus elymoides''''Elymus elymoides'' — U.C. Photo gallery
{{Clear elymoides Bunchgrasses of North America Grasses of the United States Grasses of Canada Native grasses of the Great Plains region Native grasses of California Native grasses of Nebraska Native grasses of Oklahoma Native grasses of Texas Flora of Western Canada Flora of the Northwestern United States Flora of the Southwestern United States North American desert flora Flora of the Great Basin Flora of the California desert regions Flora of the Sonoran Deserts Flora of Arizona Flora of Colorado Flora of Nevada Flora of New Mexico Flora of Utah Flora of Wyoming Flora of the Cascade Range Flora of the Klamath Mountains Flora of the Sierra Nevada (United States) Natural history of the California chaparral and woodlands Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Flora without expected TNC conservation status